Some people swear that regular sessions of acupuncture help relieve their back pain and headaches. And now there’s evidence they may be right.

In a study published in the Archives of Internal Medicine, researchers led by Andrew Vickers, an epidemiologist and biostatistician at Memorial Sloan Kettering Cancer Center, report that acupuncture is effective in reducing people’s chronic pain — more so than standard pain treatment and slightly better than using sham needles, suggesting that the benefits of real acupuncture are due to something more than the placebo effect.

The findings counter those of the last large study on the subject, which found that the needle technique was no better than a fake acupuncture treatment — using random pricking with toothpicks — in reducing people’s pain. But Vickers says his meta-analysis of the data, in which researchers reviewed 29 previous studies involving 17,922 participants, does a few things the previous studies did not. For one, he and his colleagues began by looking at only the most rigorous trials involving acupuncture and pain relief — those that directly compared acupuncture treatment with some type of sham needle therapy in which needles were either inserted only superficially or placed in locations that are not known by acupuncture standards to be key treatment points in the body. The authors of the analysis contacted each of the researchers on the previous studies to discuss with them how they separated the two treatment groups. By limiting their review to the most robust studies published, the authors could assess with more confidence acupuncture’s true effect on participants’ reports of pain before and after treatment.

Next, rather than simply summing up the total effect of acupuncture reported by researchers in previous studies, Vickers’ team asked for their raw data on individual participants’ self-reports of pain. Not all scientists use the same scale for reporting results, which makes it difficult to compare and consider such measurements of pain as a whole. With the raw data, Vickers and his team were able to standardize the participants’ responses and compare them in a more meaningful way.

The result was a clear and “robust” effect of acupuncture in relieving chronic pain in the back, neck and shoulders, as well as pain due to osteoarthritis and headaches, Vickers’ team found. Compared with people undergoing sham needle treatments, those receiving acupuncture reported drops in back and neck pain of 0.23 standard deviations, and of 0.55 standard deviations compared with those not using acupuncture at all. On a pain scale of 0 to 100, that meant that among the participants, who started out with an average baseline pain score of 60, pain ratings fell to 30 on average for those who got acupuncture, 35 for those who received fake acupuncture, and 43 for people who got usual care and no acupuncture.

“The effects of acupuncture are statistically significant and different from those of sham or placebo treatments,” says Vickers. “So we conclude that the effects aren’t due merely to the placebo effect.”

Acupuncture is an ancient Chinese remedy for a curing a host of chronic ills, from headaches to back pain and menstrual cramps. The practice, like all medical traditions from the East, is built on the concept of maintaining the balance of various body elements — including blood and nutrients along with less measurable ones like the energy force known as chi. Inserting needles at designated point on the body is supposed to intercept or unblock the flow of such elements, and lies at the heart of the centuries-old therapy of acupuncture.

However, these theories are completely foreign, even weird, to Western medicine, which has a harder time accepting unquantifiable entities such as chi. That’s why Western researchers have struggled not only to document objective evidence of acupuncture’s effectiveness, but also to provide some hints about how it may work.

Some doctors say the needles may release endorphins, the pleasure-inducing, painkilling chemicals that saturate the brain and numb pain signals. But such theories can’t fully explain why acupuncture patients say their chronic pain episodes become less frequent and less intense over time, with regular, long-term sessions. Some say the benefits of acupuncture are purely in the mind, a psychological placebo effect. But either way, for many pain patients, acupuncture does provide palpable relief.

Asks Dr. Andrew Avins in a commentary accompanying the study, if the treatment works, does it really matter whether the effect is physiological or psychological? “At least in the case of acupuncture, Vickers et al have provided some robust evidence that acupuncture seems to provide modest benefits over usual care for patients with diverse sources of chronic pain,” he writes. “Perhaps a more productive strategy at this point would be to provide whatever benefits we can for our patients, while we continue to explore more carefully all mechanisms of healing.”

In other words, if it works and doesn’t seem to lead to any harms, getting stuck with needles may not be such a weird idea after all.

Alice Park is a writer at TIME. Find her on Twitter at @aliceparkny. You can also continue the discussion on TIME’s Facebook page and on Twitter at @TIME.

My sister used to be a professional dancer. She has always had terrible back pain. I remember when she finally gave acupuncture a try. She is one of those people who swears by it. We were all just happy she found a pain reliever that worked for her. www.acupuncturepuntagorda.com

Acupuncture rocks. It's really helped me a lot. I had major cramps and PMS pain that no doctor could solve, no diet changes, no supplements nothing. Acupuncture completely eliminated my cramps in about 6 months plus it helps me have more energy and helps me heal faster when I get sick. I recommend it to everyone.

I am a skeptic about everything, but there is no denying that acupuncture has been the biggest relief of chronic migraines for my husband. At times, he was having as many as one migraine per day. They are so terribly debilitating and it just crushed me to see him suffer so badly. As a last resort, he turned to acupuncture. I don't know how it works, or why; I just know that nothing has ever provided relief for him until acupuncture. He actually received a referral from his Kaiser neurologist. Now, he has not had a migraine in 3 months. I hope it continues, and I am grateful to have my husband back.

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As an Acupuncturist of 20 years located now in Raleigh, North Carolina, and formally in Santa Fe New Mexico, I can attest to the precision and success of Acupuncture. I treat 1000's of patients every year with great success. I usually hear from my patients how they went to so many well respected Hospitals and Clinics for their ailment and have spent tens of thousands of dollars, only to have treatment with us and within short time feel better. These subjective reports are then supported very often by lab tests that show a return to their norm.

Its amazing that modern medicine has failed to fully recognize the value other healing traditions have to help Americands who are suffering from illness. Im ashamed of modern Western medicines failure to make full use of all traditions to help Americans who suffer illness.

Its amazing after Acupuncture has been in existence since before Hippocrates-that now modern western medicine recognizes it may be of value. This is a sad commentary on the bacwardness and bias of modern Western medicine that is riddled with prejudice toward other healing tradtions. Doctors in the U.S. remain riddled with biases and are very ignorant of what treatments may be of value to their patients. The need to overhaul medicine is as urgent as ever as our doctors cant get it right when it comes to helping Americans properly with illness.

@davidbecker2 I think a lot of the problem is that, even when doctors recognize that acupuncture works, no one has any real idea what physical processes cause it to work. That doesn't sit well with ANY scientist. So while some doctors may simply ignore the topic, others recognize that it works, but still want research done on it to know WHY. After all, if we could learn WHY it works, we could presumably find ways to improve it, or use similar techniques to reduce pain under other circumstances. I don't think asking "why?" is a "failure" in any sense.